The present invention relates to testing of a radio frequency (RF) data packet signal transceiver, and in particular, to testing such a device without explicit or separate synchronization signals.
Many of today's electronic devices use wireless signal technologies for both connectivity and communications purposes. Because wireless devices transmit and receive electromagnetic energy, and because two or more wireless devices have the potential of interfering with the operations of one another by virtue of their signal frequencies and power spectral densities, these devices and their wireless signal technologies must adhere to various wireless signal technology standard specifications.
When designing such wireless devices, engineers take extra care to ensure that such devices will meet or exceed each of their included wireless signal technology prescribed standard-based specifications. Furthermore, when these devices are later being manufactured in quantity, they are tested to ensure that manufacturing defects will not cause improper operation, including their adherence to the included wireless signal technology standard-based specifications.
For testing these devices following their manufacture and assembly, current wireless device test systems typically employ testing subsystems for providing test signals to each device under test (DUT) and analyzing signals received from each DUT. Some subsystems (often referred to as “testers”) include at least a vector signal generator (VSG) for providing the source signals to be transmitted to the DUT, and a vector signal analyzer (VSA) for analyzing signals produced by the DUT. The production of test signals by the VSG and signal analysis performed by the VSA are generally programmable (e.g., through use of an internal programmable controller or an external programmable controller such as a personal computer) so as to allow each to be used for testing a variety of devices for adherence to a variety of wireless signal technology standards with differing frequency ranges, bandwidths and signal modulation characteristics.
As features and manufacturing volumes of such devices increase, the time, and therefore, the cost, of testing such devices increases as well. One way to reduce the time and, therefore, the cost, of testing is to reduce the communications between the tester, or testing system, and the DUT that are not related to directly producing test results. One approach to this has been to program or otherwise embed within both the tester and DUT predetermined sequences of testing steps (e.g., pre-loaded in firmware) and provide synchronization between the tester and DUT to ensure that proper testing steps are followed as desired. Such synchronization can be achieved during brief intervals of explicit synchronization communications between the tester and the DUT. Examples of these can be found in U.S. Pat. Nos. 7,689,213 and 8,811,194, the disclosures of which are incorporated herein by reference.
However, it would be desirable to further minimize, or even eliminate, such requirements of intervals, however brief, of explicit synchronization communications, since such synchronization communications complicate design and execution of the test flow, and do not directly produce or result in test results.